Reply To: Determining the correct gear pitch for a given rack

[Pete RimmerParticipant @peterimmer30576]

Set your digital caliper to 3.142 inches and offer it up to the rack teeth. If the jaws span a number of teeth exactly then count the teeth they span – that's the equivalent DP of the rack.

If the jaws don't span whole numbers of teeth then it's a module rack. Measure across ten teeth and divide the answer by 31.42.